Changing direction of flow in a watercourse is accompanied by non-hydrostatic pressure distribution, fixed in location where the curvature is steady, and constantly shifting in location and magnitude when the deviations arc due to turbulence. The response of the subflow in the boundary soil, from high pressure areas to low pressure areas, is practically instantaneous. Erosion (or rupture of waterproof linings) is most likely to occur at the low pressure areas, where the direction of flow is from the soil into the watercourse. Terzaghi's reverse filter can be used to prevent removal of soil as long as the topmost layers of the filter remain stable. This is achieved by using the ancient Chinese rock snake or sausage. The economy and practicality of the method for new and old erosion problems are under continuing investigation, as illustrated by a 16 mm silent motion picture prepared by the author.
Proceedings of the Iowa Academy of Science
©1962 Iowa Academy of Science, Inc.
Posey, C. J.
"Protection of Soil From Erosion by Swiftly Flowing Water,"
Proceedings of the Iowa Academy of Science, 69(1), 307-309.
Available at: https://scholarworks.uni.edu/pias/vol69/iss1/50